The invention is concerned with electrical connectors and particularly, although not exclusively, with electrical connectors which are used in the trucking industry for interconnecting tractor-trailer jumper cables.
Seven-conductor electrical connectors for tractor-trailer jumper cables have become a standard item in the trucking industry. These connectors are subject to SAE standards, such as SAE Standard J560. The jumper cables themselves are also subject to SAE standards, such as SAE Standard J1067.
Originally the housings of the connectors were constructed of an appropriate metal. However, there has been a trend in recent years to make the connector housings out of plastic. Problems have arisen, however, especially in the case of the plastic housings, in that it has been found that under extreme conditions, there is a tendency for the plug and socket of the electrical connectors to pull apart when in a latched condition. This can create a hazardous condition, since it immediately causes all electric power to the trailer to be disconnected.
An electrical connector, such as referred to above, is disclosed, for example, in
U.S. Pat. No. 4,786,261, which issued Nov. 22, 1988 in the name of the present inventor. Other similar connectors for tractor-trailer use are described, for example, in U.S. Pat. Nos. 4,072,381 and 4,304,457. All of the connectors referred to above include a plug which is connected to appropriate jumper cables, and a socket which is mounted on the tractor cab. After the plug has been plugged into the socket, the plug and socket are latched together by an appropriate latch formed on the cover of the socket.
As mentioned above, although the latching assembly provides an adequate lock between the plug and socket under normal conditions, it has been found that there is a tendency for the plug to pull out from the socket under some conditions. An objective of the present invention is to provide a simple and inexpensive construction which overcomes that problem.